Adhesive Small-Bowel Obstruction: Value of CT in Identifying Findings Associated with the Effectiveness of Nonsurgical Treatment

This retrospective study of imaging findings in patients with SBO due to adhesions is mostly valuable because the author's have tried to actually correlate the findings to actual impact on management. It is a moderate sized review of 221 patients with SBO on CT, and review of findings on those studies. The specific features they identify as predictive of successful non-operative management is the presence of fewer than two beak signs and the presence of an anterior parietal adhesion are predictive of successful non-operative management. U shaped or C shaped loops were predictive of non-operative management failure.

PICO Analysis:
Population: patients with SBO on CT
Intervention: non-operative management
Comparison: none
Outcome: successful non-operative management

Reference: Pubmed Full Text

Diagnostic accuracy and patient acceptance of MRI in children with suspected appendicitis

This prospective study compares 3 strategies for imaging suspected appendicitis. Ultrasound alone, US+conditional MRI and MRI alone. The sensitivity of MRI alone and US + conditional MRI was 100%, ultrasound alone was found to be significantly lower at 76%.
The specificity was found to be comparable among the three investigated strategies; MRI alone 89%, US + conditional MRI 80% and US alone 89%.

The study on a technical basis is quite good, with patients enrolled consecutively and prospectively. Surgical diagnosis or 3mo followup including contact of all patients primary physician was used for clinical followup. While no flowchart is provided in the text documenting the different arms it appears none were lost to followup and all 'positive' cases did proceed to surgery. The study population had a relatively high prevalence of appendicitis at 56%.

Limitations are that the US was performed by radiology residents, and the surgical management is not clear for all cases which makes assessment of the applicability of these results to different practices (such as in Canada or US) somewhat challenging, and may explain the relatively low sensitivity of US alone despite relatively high subjective quality evaluation of the US studies.

PICO Analysis:
Population: pediatric patients 4-18yo (mean 12yo)
Intervention: US alone, MRI alone or US + conditional MRI
Comparison: Surgical dx or 3mo clinical followup
Outcome: Sensitivity and Specificity

Reference: Pubmed Full Text

Comparison of Imaging Strategies with Conditional Contrast-enhanced CT and Unenhanced MR Imaging in Patients Suspected of Having Appendicitis: A Multicenter Diagnostic Performance Study.

Prospective study of 230 patients with suspected appendicitis. All underwent MRI, and remainder followed clinical pathway with US +/- CT. the results of immediate MRI, conditional MRI after US and conditional CT after US were analyzed. 

Conditonal CT missed appendicitis in 3%, with 8% (10 of 125; 95% CI: 4%, 14%) false-positives.
Conditional MR missed appendicitis in 2% with 10% (13 of 129; 95% CI: 6%, 16%) false-positives.
Immediate MR missed appendicitis in 3% with 6% (seven of 120; 95% CI: 3%, 12%) false-positives.

While no consistent gold standard was applied in this study, the similar results of conditional or staged MRI and CT after inconclusive or negative US are impressive, and support the possibility of using MRI in suspected appendicitis when ionizing radiation from CT is a concern. No information on bmi or detailed demographics were provided to assess for applicability or correlate with results from the paediatric radiology literature.

PICO Analysis:
Population: adult patients with suspected appendicitis
Intervention: unenhanced MRI
Comparison: unenhanced MRI after ultrasound and CT after ultrasound
Outcome: expert consensus (surgeons and radiologists)

Reference: Leeuwenburgh MM et al., Radiology, July 2013, 268(1):135-143.
Links:  Pubmed Full Text

Is Early Colonoscopy Beneficial in Patients With CT-Diagnosed Diverticulitis?

Elmi et al evaluated 402 patients with acute diverticulitis diagnosed on a contrast enhanced CT with subsequent colonoscopy.  Retrospectively, they looked at the complications of diverticulitis as markers for underlying carcinoma.   The presence of mesenteric or retroperitoneal lymph nodes and bowel obstruction were the highest risk factors for underlying colonic carcinoma (odds ratio of 23 and 24 respectively).  The presence of an abscess is also slightly associated with underlying carcinoma (odds ratio of 4).  Prior studies demonstrated that the presence of fisutulous tracts and perforation were also markers for underlying carcinoma (see link below).  This was not demonstrated on this study.

The incidence of carcinoma in this study was low at 9 cancers in the 402 patients included. 8 of the 9 cancers were diagnosed within 6 months of the initial presentation.
19% of the 402 patients had underlying colonic polyps.  The presence of "obvious" subjective enhancement was highly associated with underlying polyps or carcinoma.

Population: mean age of 63.3 (range 50-94)
Intervention: Colonoscopy post diagnosis of acute diverticulitis (retrospective analysis)
Comparison: the presence of complications associated with acute diverticulitis (obstruction, lymph nodes,  and associated lymph nodes)
Outcome: The presence of bowel obstruction and enlarged lymph nodes is highly associated with underlying carcinoma in patients with diverticulitis.

Links: Pubmed, Original article

Related literature: Is colonoscopy still mandatory after a CT diagnosis of left-sided diverticulitis: can colorectal cancer be confidently excluded?

Elmi et al (2013). American Journal of Radiology. 200: 1269-1274